Absorbent articles having improved longitudinal fluid movement

ABSTRACT

The present invention provides absorbent articles, especially sanitary napkins, containing a flow regulator positioned between the topsheet and the absorbent core. In-use, fluid deposited on the topsheet is internally moved in the longitudinal direction by the flow regulator before being released to the absorbent core. By moving substantial amounts of fluid in the longitudinal direction the flow regulator provides a more effective use of the absorbent core.

TECHNICAL FIELD

The present invention relates to absorbent articles especiallycatamenial articles such as sanitary napkins. Such articles areespecially adapted for absorbing various body fluids, especially menses,while providing comfort and fit to the wearer.

BACKGROUND OF THE INVENTION

A wide variety of structures for disposable absorbent articles tocollect body fluids are known in the art. Commercial absorbent articlesinclude diapers, adult incontinence products, catamenials and bandages.Disposable products of this type comprise some functional members forreceiving, absorbing and retaining fluids. Generally, such absorbentarticles contain a core of absorbent materials mainly comprising fibrouscellulose. Typically, such articles include a fluid-permeable topsheet,an absorbent core and a fluid-impermeable backsheet.

In the case of catamenial pads, women have come to expect a high levelof performance in terms of comfort and fit, retention of fluid, andminimal staining. Above all, leakage of fluid from the pad ontoundergarments is regarded as totally unacceptable.

Improving the performance of sanitary napkins continues to be aformidable undertaking, although a number of improvements have been madein both their materials and structures. However, eliminating leakage,particularly along the inside of the thighs, without compromising fitand comfort, has not met the desired needs of the consumer.

Leakage from sanitary napkins is generally attributed to a highconcentration of fluid at the point where the menses exits the body andimmediately contacts the surface of the napkin. At this point ofdeposit, the napkin's absorbent material quickly becomessuper-saturated. The menses migrates radially from this point and leaksfrom the sides nearest the wearer's legs. This often results in thesmearing of menses on the body and soiling of the undergarments.Attempts to eliminate leakage include: construction of a densified edgeto hold the fluid back (U.S. Pat. No. 4,820,295, Chapas et al, issuedApr. 11, 1989); barrier sheets surrounding the article (U.S. Pat. No.4,666,439, Williams et al, issued May 19, 1987); and "winged" side edgeswhich wrap around the panties (U.S. Pat. No. 4,701,177, Ellis et al,issued Oct. 10, 1987, incorporated herein by reference).

Unfortunately, overdensifying sections of the sanitary napkins detractsfrom comfort, in-use. Some users are not attracted to the "winged"product, and others are not satisfied with the barrier product. However,since a large part of most absorbent articles remains relatively dry andnot utilized, it has now been determined that providing a means todirect fluid from the point of deposit to the areas of the article notfully utilized will avoid super-saturation and considerably reduce oreliminate leakage.

Apart from undergarment soiling, the user of modern sanitary napkins,and the like, has come to expect that the surface of such articles willprovide a cleaner, more sanitary and drier aspect than common cloth ornonwoven materials have historically provided. Thus, modern sanitarynapkins, diapers and incontinence devices are typically provided withtopsheets that are designed to move fluids rapidly through saidtopsheets and into an underlying absorbent core for storage. As can beenvisaged, the more rapid and thorough this movement, the drier andcleaner the surface of the article.

Stated succinctly, the present invention not only provides the desired,directional movement of fluids noted above, which allows improved use ofthe overall absorbent capacity of the article and less side-leakage, butalso provides means to draw fluids through the topsheet, therebyenhancing the desired dry, sanitary benefits, in-use.

Furthermore, the articles which employ the technology embodied in thepresent invention are more comfortable and better fitting than articleswhich rely, for example, on highly dense absorbent core regions toachieve fluid movement. Stated otherwise, the technology herein achievesthe fluid directionality and handling characteristics available fromdense, but uncomfortable, cores in a soft, pliable, low-density andcomfortable pad.

SUMMARY OF THE INVENTION

The present invention pertains, in a preferred embodiment, to absorbentarticles, preferably a sanitary napkin or pantiliner, but also includesdiapers, adult incontinence garments, bandages, and the like. Theabsorbent article has a longitudinal direction, a transverse direction,and a z-direction. The absorbent article includes a fluid pervioustopsheet and a fluid impervious backsheet joined to the topsheet. Anabsorbent core is positioned between the topsheet and the backsheet. Thecore has an uppermost surface facing topsheet and a lowermost surfacefacing the backsheet. A flow regulator is positioned between thetopsheet and the absorbent core. The flow regulator enhances movement offluid in the longitudinal direction while controlling movement of fluidin the transverse and z-directions.

In a preferred embodiment the flow regulator comprises a secondarytopsheet and a plurality of fibers having external capillary channels.Preferably, the secondary topsheet is arranged in a plurality of pleatsextending substantially parallel to the longitudinal direction of theabsorbent article. The fibers having external capillary channels areformed into a yarn and positioned within the pleats of the secondarytopsheet. The yarn of fibers positioned within the pleats of thesecondary topsheet is twisted.

In another preferred embodiment, the fibers having external capillarychannels are formed into a nonwoven. The nonwoven comprised of fibershaving external capillary channels is superposed upon the secondarytopsheet. The fibers having external capillary channels of the nonwovenare preferably oriented such that their channels lie substantiallyparallel to the longitudinal direction of the article. Preferably, thefibers having external capillary channels are hydrophilic. Preferably,the capillary channel fibers have a "H"-shaped cross-section.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming the present invention, it is believed that thepresent invention will be better understood from the followingdescription in conjunction with the accompanying drawings, in which likereference numbers identify identical elements and wherein;

FIG. 1 is a top plan view of a preferred sanitary napkin of the presentinvention with portions cut-away to more clearly show the constructionof the sanitary napkin;

FIG. 2 is a cross-sectional view of the sanitary napkin of FIG. 1 takenalong line 2--2;

FIG. 3 is a cross-sectional view of a symmetrical "H"-shaped capillarychannel fiber with a planar base (4), width between walls (5), anddepth-of-walls (6);

FIG. 4 is a cross-sectional view of a "C" shaped capillary channel fiberhaving stabilizing legs depending therefrom;

FIG. 5 is a cross-sectional view of a multiple "H"-shaped capillaryfiber;

FIG. 6 is a cross-sectional view of a multiple "U"-shaped capillarychannel fiber;

FIG. 7A is a cross-sectional view of an H-shaped capillary channel fiberin a partially collapsed state; (While not optimal, such fibers can beused herein);

FIG. 7B is a cross-sectional view of an expanded capillary channelfiber;

FIG. 7C is a cross-sectional view of a wholly collapsed capillarychannel fiber; (Such fibers are not used herein);

FIG. 8 is a photomicrograph sectional view taken of a sanitary napkinwhich shows the close contact between a formed film topsheet and anunderlying layer of capillary channel fibers and the protrusion ofcapillary channel fibers into the pores of the topsheet;

FIG. 9 is a top plan view of another embodiment of the sanitary napkinof the present invention with portions cut-away to more clearly show theconstruction of the sanitary napkin; and

FIG. 10 is a cross-sectional view of the sanitary napkin of FIG. 9 takenalong line 10--10.

DETAILED DESCRIPTION OF THE INVENTION 1. General Description of theAbsorbent Article

As used herein, the term "absorbent article" refers to devices whichabsorb and contain body exudates, and, more specifically, refers todevices which are placed against or in proximity to the body of thewearer to absorb and contain the various exudates discharged from thebody. The term "absorbent article" is intended to include diapers,catamenial pads, sanitary napkins, pantiliners, incontinent pads, andthe like. The term "disposable" is used herein to describe absorbentarticles which are not intended to be laundered or otherwise restored orreused as an absorbent article (i.e., they are intended to be discardedafter a single use, and, preferably, to be recycled, composted orotherwise disposed of in an environmentally compatible manner). A"unitary" absorbent article refers to absorbent articles which areformed of separate parts united together to form a coordinated entity sothat they do not require separate manipulative parts like a separateholder and pad.

A preferred embodiment of a unitary disposable absorbent article of thepresent invention is the catamenial pad, sanitary napkin 20, shown inFIG. 1. As used herein, the term "sanitary napkin" refers to anabsorbent article which is worn by females adjacent to the pudendalregion, generally external to the urogenital region, and which isintended to absorb and contain menstrual fluids and other vaginaldischarges from the wearer's body (e.g., blood, menses, and urine).Interlabial devices which reside partially within and partially externalof the wearer's vestibule are also within the scope of this invention.As used herein, the term "pudendal" refers to the externally visiblefemale genitalia. It should be understood, however, that the presentinvention is also applicable to other feminine hygiene or catamenialpads such as pantiliners, or other absorbent articles such asincontinence pads, and the like.

The sanitary napkin 20 has two surfaces, a body-contacting surface or"body surface" 20a and a garment surface 20b. The sanitary napkin 20 isshown in FIG. 1 as viewed from its body surface 20a. The body surface20a is intended to be worn adjacent to the body of the wearer. Thegarment surface 20b of the sanitary napkin 20 (shown in FIG. 2) is onthe opposite side and is intended to be placed adjacent to the wearer'sundergarments when the sanitary napkin 20 is worn.

The sanitary napkin 20 has two centerlines, a longitudinal centerline"l" and a transverse centerline "t". The term "longitudinal", as usedherein, refers to a line, axis or direction in the plane of the sanitarynapkin 20 that is generally aligned with (e.g., approximately parallelto) a vertical plane which bisects a standing wearer into left and rightbody halves when the sanitary napkin 20 is worn. The terms "transverse"or "lateral" as used herein, are interchangeable, and refer to a line,axis or direction which lies within the plane of the sanitary napkin 20that is generally perpendicular to the longitudinal direction.

FIG. 1 is a top plan view of the sanitary napkin 20 of the presentinvention in its flat-out state with portions of the structure beingcut-away to more clearly show the construction of the sanitary napkin 20and with the portion of the sanitary napkin 20 which faces or contactsthe wearer 20a, oriented towards the viewer. As shown in FIG. 1, thesanitary napkin 20 preferably comprises a liquid pervious topsheet 22, aliquid impervious backsheet 23 joined with the topsheet 22, an absorbentcore 24 positioned between the topsheet 22 and the backsheet 23, and aflow regulator 21 positioned between the topsheet 22 and the absorbentcore 24.

FIG. 1 also shows that the sanitary napkin 20 has a periphery 30 whichis defined by the outer edges of the sanitary napkin 20 in which thelongitudinal edges (or "side edges") are designated 31 and the end edges(or "ends") are designated 32.

Sanitary napkin 20 preferably includes optional side flaps or "wings" 34that are folded around the crotch portion of the wearer's panties. Theside flaps 34 can serve a number of purposes, including, but not limitedto protecting the wearer's panties from soiling and keeping the sanitarynapkin secured to the wearer's panties.

FIG. 2 is a cross-sectional view of the sanitary napkin 20 taken alongsection line 2--2 of FIG. 1. As can be seen in FIG. 2, the flowregulator 21 preferably comprises a secondary topsheet 27 and aplurality of fibers 25 having external capillary channels. The secondarytopsheet 27 preferably includes plurality of pleats 26 extendingsubstantially parallel to the longitudinal direction of the sanitarynapkin 20. The fibers 25 having external capillary channels arepreferably positioned within pleats 26 of the secondary topsheet 27.

The sanitary napkin 20 preferably includes an adhesive fastening means36 for attaching the sanitary napkin 20 to the undergarment of thewearer. Removable release liners 37 cover the adhesive fastening means36 to keep the adhesive from sticking to a surface other than the crotchportion of the undergarment prior to use.

In addition to having a longitudinal direction and a transversedirection, the sanitary napkin 20 also a "z" direction or axis, which isthe direction proceeding down through the topsheet 22 and into whateverfluid storage core 24 that may be provided. The objective is to providea gradient of capillary suction between the topsheet 22 and underlyinglayer or layers of the articles herein, such that fluid is eventuallydrawn in the "z" direction and away from the topsheet of the articleinto its ultimate storage layer.

By employing a flow regulator which preferably comprises a secondarytopsheet arranged in a plurality of longitudinal pleats in which ispositioned a plurality of fibers having external capillary channels,fluid flow in the longitudinal direction is promoted, which enhances theoverall useful absorbency of the article. Moreover, fluid flow in thetransverse direction is controlled, thereby minimizing, or even entirelyavoiding, leakage of fluid around the lateral edges of the article.Thus, unlike absorbent articles of the prior art which move fluids in anundirected manner in the x, y and z directions by means of fibrous battswhich comprise inter-fiber capillary voids, the flow regulator hereincan be used to provide desirable fluid directionality. Thus, it will beappreciated that the absorbent articles of this invention function in asubstantially different way, using substantially different materials toprovide substantially different benefits than the various art-disclosedabsorbent structures which do not employ a flow regulator preferablycomprised of a secondary topsheet and fibers having external intrafibercapillary channels to promote the passage of bodily fluids in thelongitudinal direction.

The individual components of the sanitary napkin will now be looked atin greater detail.

2. Individual Components of the Sanitary Napkin

A. The Topsheet

The topsheet 22 is compliant, soft feeling, and non-irritating to thewearer's skin. Further, the topsheet 22 is liquid pervious permittingliquids (e.g., menses and/or urine) to readily penetrate through itsthickness. A suitable topsheet 22 may be manufactured from a wide rangeof materials such as woven and nonwoven materials; polymeric materialssuch as apertured formed thermoplastic films, apertured plastic films,and hydroformed thermoplastic films; porous foams; reticulated foams;reticulated thermoplastic films; and thermoplastic scrims. Suitablewoven and nonwoven materials can be comprised of natural fibers (e.g.,wood or cotton fibers), synthetic fibers (e.g., polymeric fibers such aspolyester, polypropylene, or polyethylene fibers) or from a combinationof natural and synthetic fibers.

A preferred topsheet 22 comprises an apertured formed film. Aperturedformed films are preferred for the topsheet because they are pervious tobody exudates and yet non-absorbent and have a reduced tendency to allowliquids to pass back through and rewet the wearer's skin. Thus, thesurface of the formed film which is in contact with the body remainsdry, thereby reducing body soiling and creating a more comfortable feelfor the wearer. Suitable formed films are described in U.S. Pat. No.3,929,135 issued to Thompson on Dec. 30, 1975; U.S. Pat. No. 4,324,246issued to Mullane et al. on Apr. 13, 1982; U.S. Pat. No. 4,342,314issued to Radel et al. on Aug. 3, 1982; U.S. Pat. No. 4,463,045 issuedto Ahr et al. on Jul. 31, 1984; U.S. Pat. No. 4,629,643 issued to Curroet al. on Dec. 16, 1986; and U.S. Pat. No. 5,006,394 issued to Baird onApr. 9, 1991. Each of these patents are incorporated herein byreference. The preferred topsheet 22 for the present invention is theformed film described in one or more of the above patents and marketedon sanitary napkins by The Procter & Gamble Company of Cincinnati, Ohioas "DRI-WEAVE".

In a preferred embodiment of the present invention, the body surface ofthe formed film topsheet 22 is hydrophilic so as to help liquid totransfer through the topsheet 22 faster than if the body surface was nothydrophilic. This will diminish the likelihood that menstrual fluid willflow off the topsheet 22 rather than flowing into and being absorbed bythe absorbent core 24. In a preferred embodiment, surfactant isincorporated into the polymeric materials of the formed film topsheet 22such as is described in U.S. patent application Ser. No. 07/794,745entitled "Absorbent Article Having A Nonwoven and Apertured FilmCoversheet" filed on Nov. 19, 1991 by Aziz et al. Alternatively, thebody surface of the topsheet 22 can be made hydrophilic by treating itwith a surfactant such as is described in U.S. Pat. No. 4,950,264 issuedto Osborn on Aug. 21, 1991 and U.S. Pat. No. 5,009,653 issued to Osbornon Apr. 23, 1991 both of which are incorporated herein by reference.

B. The Absorbent Core

The absorbent core 24 may be any absorbent means which is capable ofabsorbing or retaining liquids (e.g., menses and/or urine). As shown inFIGS. 1 and 2, the absorbent core 24 has a body surface, a garmentsurface, side edges, and end edges. The absorbent core 24 may bemanufactured in wide variety of sizes and shapes (e.g., rectangular,oval, hourglass, dog bone, asymmetric, etc.) and from a wide variety ofliquid-absorbent materials commonly used in sanitary napkins and otherabsorbent articles such as comminuted wood pulp which is generallyreferred to as airfelt. An example of other suitable absorbent materialsinclude creped cellulose wadding; meltblown polymers including coform;chemically stiffened, modified or cross-linked cellulosic fibers;capillary channel fibers; synthetic fibers such as crimped polyesterfibers; peat moss; tissue including tissue wraps and tissue laminates;absorbent foams; absorbent sponges; superabsorbent polymers; absorbentgelling materials; or any equivalent material or combinations ofmaterials, or mixtures of these.

The configuration and construction of the absorbent core 24 may also bevaried (e.g., the absorbent core may have varying caliper zones (e.g.,profiled so as to be thicker in the center), hydrophilic gradients,superabsorbent gradients, or lower density and lower average basisweight acquisition zones; or may comprise one or more layers orstructures). The total absorbent capacity of the absorbent core 24should, however, be compatible with the design loading and the intendeduse of the sanitary napkin 20. Further, the size and absorbent capacityof the absorbent core 24 may be varied to accommodate different usessuch as incontinence pads, pantiliners, regular sanitary napkins, orovernight sanitary napkins.

Exemplary absorbent structures for use as the absorbent core 24 of thepresent invention are described in U.S. Pat. No. 4,950,264 issued toOsborn on Aug. 21, 1990; U.S. Pat. No. 4,610,678 issued to Weisman etal. on Sep. 9, 1986; U.S. Pat. No. 4,834,735 issued to Alemany et al. onMay 30, 1989; U.S. Pat. No. 5,009,653 issued to Osborne on Apr. 23,1991; and European Patent Application No. 0 198 683, The Procter &Gamble Company, published Oct. 22, 1986 in the name of Duenk et al. Eachof these patents are incorporated herein by reference.

A preferred embodiment of the absorbent core 24 comprises the laminatestructure shown in FIG. 2. The laminate is comprised of a layer ofsuperabsorbent polymeric (or absorbent gelling material) and one or moresheets or webs of cross-linked cellulosic fibers. Suitable cross-linkedcellulosic fibers for the absorbent core 24 are described in U.S. Pat.No. 4,888,093 issued to Cook et al. on Dec. 19, 1989; U.S. Pat. No.4,822,543 issued to Dean et al. on Apr. 18, 1989; U.S. Pat. No.4,889,595 issued to Schoggen et al. on Dec. 26, 1989; and U.S. Pat. No.4,898,642 issued to Moore et al. on Feb. 6, 1990; U.S. Pat. No.4,935,022 issued Jun. 19, 1990 to Lash et al.; EPO Patent ApplicationPublication Nos. 0 427 316 A2 and 0 427 317 A2 published in the name ofHerron et al. on May 15, 1991; and EPO Patent Application PublicationNo. 0 429 112 A2 published in the name of Herron et al. on May 29, 1991incorporated herein by reference.

The cross-linked cellulosic fibers in the embodiment shown in FIG. 2comprises a single sheet that wraps the layers of particles of absorbentgelling material 40. The sheet is wrapped so that it appears as having a"c" configuration when viewed from the end. The wrapped sheet forms anupper layer 41 and a lower layer 42. In alternative embodiments, thelaminate can be formed in many other manners, such as by providingseparate webs of cross-linked cellulosic material (or other absorbentmaterial) for the different layers of the absorbent core laminate otherthan a single sheet, or by providing it with additional layers.

In this type of core, curled, twisted, preferably chemically stiffenedand cross-linked, cellulose fibers are refined to provide fibers whichcan be used in sheet form as the absorbent core. The preparation ofsuitable curled, chemically stiffened cellulosic fibers from which onecan prepare the refined, curled, chemical stiffened cellulosic fibersused in detail in U.S. Pat. Nos. 4,888,903; 4,822,543; 4,889,595;4,889,597; 4,889,596; and 4,898,642.

The use of such fibers in combination with absorbent gelling materials,and means for manufacturing such combinations, are described in U.S.Pat. No. 4,935,022. Such preparations typically involve the use ofaldehydes, such as glutaraldehyde, as crosslinking agents. In addition,polycarboxylic acids can be used as crosslinking agents. It will beappreciated that other means for preparing other crosslinked cellulosicfibers are also known, and such fibers may also be used herein, althoughthe fluid absorbency properties may be suboptimal as compared with theabove-mentioned fibers. Reference can be made to the various citationsin U.S. Pat. No. 4,898,642 and PCT U.S. 89 01581 for other fiber types.Once in hand, the curled cellulosic fibers are refined to provide thefibers used to prepare the preferred absorbent cores used in thepractice of this invention.

C. Backsheet

The backsheet 23 is impervious to liquids (e.g., menses and/or urine)and is preferably manufactured from a thin plastic film, although otherflexible liquid impervious materials may also be used. As used herein,the term "flexible" refers to materials which are compliant and willreadily conform to the general shape and contours of the human body. Thebacksheet 23 prevents the exudates absorbed and contained in theabsorbent core 24 from wetting articles which contact the sanitarynapkin 20 such as pants, pajamas and undergarments. The backsheet 23 maythus comprise a woven or nonwoven material, polymeric films such asthermoplastic films of polyethylene or polypropylene, or compositematerials such as a film-coated nonwoven material. Preferably, thebacksheet is a polyethylene film having a thickness of from about 0.012mm (0.5 mil) to about 0.051 mm (2.0 mils). Exemplary polyethylene filmsare manufactured by Clopay Corporation of Cincinnati, Ohio, under thedesignation P18-0401 and by Ethyl Corporation, Visqueen Division, ofTerre Haute, Ind., under the designation XP-39385. The backsheet 23 ispreferably embossed and/or matte finished to provide a more clothlikeappearance. Further, the backsheet 23 may permit vapors to escape fromthe absorbent core 24 (i.e., breathable) while still preventing exudatesfrom passing through the backsheet 23.

D. Flow Regulator

The flow regulator 21 may be any means which is capable of acquiring anddistributing liquids (e.g., menses and/or urine). It is important thatthe flow regulator 21 maintain a proper balance in the movement of fluidin the longitudinal and z-directions. The flow regulator must be able tomove the fluid substantially in the longitudinal direction prior tosurrendering the fluid to the underlying absorbent core. By moving fluidsubstantially in the longitudinal direction the flow regulator providesa more effective use of the absorbent core. The flow regulator 21preferably comprises a secondary topsheet 27 and a plurality of fibershaving external intrafiber capillary channels 25.

(i) Secondary Topsheet

The secondary topsheet 27 may be any means which is capable of acquiringand distributing liquids (e.g., menses and/or urine). As shown in FIG. 2the secondary topsheet 27 has a body surface, a garment surface, sideedges and end edges. In addition the secondary topsheet 27 is gatheredsuch that it provides a plurality of pleats 26 that extend substantiallyparallel to the longitudinal direction of the sanitary napkin 20. Thesecondary topsheet 27 helps to distribute and move fluid that has beendeposited upon the topsheet 22. The secondary topsheet 27 may thuscomprise a layer of material capable of being formed into pleats, andhaving interfiber capillaries such that fluid is transferred from thetopsheet through to the core.

Preferably, the secondary topsheet 27 is a tissue having a basis weightof from about 0.025 g/in² to about 0.045 g/in² and a density of fromabout 0.06 to 0.11 g/cm³. Exemplary tissues are manufactured by the FortHoward corporation, Green Bay, Wisc.

(ii). The Capillary Channel Fibers

The sanitary napkin 20 preferably has a plurality of capillary channelfibers 25 that are positioned within the longitudinal pleats 26 of thesecondary topsheet 27 and generally between the secondary topsheet 27and the topsheet 22. Capillary channel fibers 25 are fibers havingchannels formed therein, preferably, on their exterior surfaces. FIGS. 3to 7 show examples of some types of capillary channel fibers 25.Suitable capillary channel fibers are described below, and in thefollowing Patent Applications which were filed on Jul. 23, 1991: U.S.patent applications Ser. No. 07/734,404 filed in the names of Thompsonet al.; U.S. patent application Ser. No. 07/734,392 filed in the namesThompson et al.; and, U.S. patent application Ser. No. 07/734,405 filedin the names of Buenger et al. These patent applications may be referredto collectively as the "Capillary Channel Fiber" patent application.Suitable capillary channel fibers are also described in EPO PatentApplication 0 391 814 published Oct. 10, 1990.

While a variety of capillary channel fibers can be used herein, thefollowing description discusses some preferred characteristics of thecapillary channel fiber 25 that are incorporated into the absorbentarticles of this invention.

(a). Fiber Morphology

The capillary channel fibers 25, as noted above, have capillary channels29 on their outer surfaces. The capillary channel fibers 25 arepreferably bent or, most preferably, are in a curled configuration (thatis, they are nonlinear). Most preferably, the capillary channel fibers25 are "substantially curled" (or otherwise gathered). This provides thecapillary channel fibers with a higher loft and increased resilience fora given number of fibers. By increasing the loft of the individualfibers, the overall loft of pads made therefrom is thicker and softer.This allows for the formation of low density, high loft pads which,assuming that the individual fibers themselves are not too thick orstiff are extremely comfortable, yet effective for transporting fluids.

However, the preferred nonlinear capillary channel fibers herein shouldnot be "kinked". Kinking a capillary channel fiber can cause points ofconstriction of the capillary channels at each kinking site. This, ofcourse, would interfere with fluid flow dynamics along the capillarychannel.

In addition, there is another substantial advantage to employingnonlinear capillary channel fibers. As indicated in FIG. 8, it may bepreferred that small portions, of the capillary channel fibers 25actually protrude into at least some of the topsheet 22 orifices 35 ofthe articles herein. These protrusions are easier to effect when acapillary channel pad is prepared using curled capillary channel fibers.There is a greater likelihood that a number of ends and/or curls in thecapillary channel fibers will find their way into the orifices of thetopsheet material than if substantially linear capillary channels wereto be employed. The capillary channel fibers 25 may be curled in anumber of ways, including but not limited to: (1) selectively heatquenching the fibers as they come from their forming die by heating oneside of the fibers a bit more than the other side (or, conversely, bycooling one side more quickly than the other); (2) fibers made fromsynthetic polymers such as polyesters can be curled by stretching,followed by relaxation, or by passing the fiber under tension around asharp edge, followed by relaxation; or (3) by immersion in methanol. Ina preferred mode, the fibers are substantially helical. Whatever meansare used to crimp or otherwise curl the capillary channel fibers, theycan, if desired, then be carded to form an assembly of fibers.

The preferred amplitude of the curls is in the range of about 0.1 mm toabout 5 mm, and, typically, the frequency of the curls is from about 1per inch of fiber to about 10 per inch of fiber. Fibers with amplitudesof about 0.5 mm and a frequency of about 6 crimps per inch exhibit goodsoftness even in the higher denier ranged fibers having large capillarychannels.

(b). Fiber Structure and Surface Properties

The capillary channel fibers 25 used herein can be prepared from anyconvenient polymer which is nonswelling when wet. Polymers such aspolyethylene, polypropylene, polyesters (preferred), and the like, areuseful herein, so long as they are spinnable such that they can beformed with external capillary channels, as noted hereinabove.Conveniently, the polymers are melt-extrudable. Typically, the capillarychannel fibers herein will be prepared from a synthetic polyethyleneterephthalate polymer melt having an inherent viscosity ("IV") of fromabout 0.6 to about 0.9. (IV is a term of art and can be determined inwell-known fashion. See, for example, U.S. Pat. No. 4,829,761 at column8.) The IV of a polymer melt bears some relationship to the ability ofthe polymer to retain the shape of the capillary channel walls, and isrelated to the average molecular weight of the polymers. For example, itis convenient to employ a polyester having an inherent viscosity ofabout 0.7 herein, but it would be more preferred to employ a polymerhaving an inherent viscosity of about 0.9, since this would allow thewalls of the capillary channels to be thinner, yet sufficiently strongto avoid collapse under in-use pressure.

The capillary channel fibers 25 preferably have a denier of about 10 toabout 22. However, it is to be understood that the denier of the fibersused is within the discretion of the formulator, and the denter perfiber can easily be in the range of about 25 to about 35.

The depth:width ratio of the capillary channels herein is preferablyabout 2.0, but processing restrictions, as noted above, as well as foreconomic reasons, a depth:width ratio of about 1.3 is typicallyemployed. Typical and readily producible capillary channel fibers whichare quite satisfactory for use herein thus have a depth-of-walls ofabout 46 microns and a width-between-walls of about 33 microns. Thewalls, themselves, are typically about 3-15 microns thick. Althoughvariations in these dimensions are acceptable, capillary channel fibersprepared from polyester and having these characteristics are quiteeffective for their intended purpose. Such fibers can be prepared usingconventional operating equipment and readily withstand pressures of thetype encountered in sanitary devices, especially sanitary napkins andpantiliners, without collapse or spreading of the capillary channelwalls to such an extent that their capillary function is lost.

The capillary channels 29 can be of various shapes. Certain shapes canoffer particular advantages in particular product applications. Forexample, "U"-shaped, "H"-shaped, "C"-shaped with stabilizing legsdepending therefrom and "V"-shaped capillary channels 25 may be used.Furthermore, the basic shapes may be repeated (see Figures), or evenbranched, to produce fibers containing multiple channels, but it will beappreciated that when more than about three repeating shapes are used,some additional stiffness may be noted in the fibers. The multiple "U"fibers of FIG. 6 offer the additional advantages of having additionalcapillarity due to face-to-fate contact and being easily curled.

The manufacture of capillary channel fibers 25 of the type employedherein is described in EPO Application 391,814 and in co-pending U.S.Continuation-In-Part Application entitled "Fibers Capable ofSpontaneously Transporting Fluids", Ser. No. 07/736,261, filed Jul. 23,1991, Inventors Phillips, Jones et al., Eastman Chemical Company;co-pending U.S. Patent Application entitled "Spinneret Orifices andFilament Cross-Sections with Stabilizing Legs Therefrom", Ser. No.07/918,174, filed Jul. 23, 1992, Inventors Phillips, et al.; and inco-pending U.S. patent application entitled "Open Capillary ChannelStructures, Improved Process for Making Capillary Channel Structures,and Extrusion Die for Use Therein", Ser. No. 07/482,446, filed Feb. 20,1990, inventors Thompson and Krautter.

While the polymers used to prepare the capillary channel fibers hereinare not, themselves, water-absorbent (nor are they absorbent to urine orblood-containing fluid such as menses), the fibers themselves are mostpreferably hydrophilic. Since most synthetic polymers are hydrophobic,the capillary channel fibers herein are surface-treated in order torender them hydrophilic.

The surface treatment of polymeric fibers involves processes which arewell-known in the extensive fiber literature. In general, such processesinvolve treating the surface of the fibers with a "hydrophilizingagent", especially a surfactant. (Hydrophilization, which results inwettability of the fibers by aqueous fluids, can routinely be measured,for example, using contact angle measurements. In general, a contactangle less than 90° indicates a hydrophilic surface. A CAHN SurfaceForce Analyzer (SFA 222) can be used to measure hydrophilicity, as can avariety of other instruments known in the art.) Typical surfactantuseful in such processes include various nonionic and anionic detersivesurfactants of the general type known in the laundry literature.Hydrophilizing agents include wetting agents such as polyethylene glycolmonolaurates (e.g., PEGOSPERSE 200ML, a polyethylene glycol 200monolaurate available from Lonza, Inc., Williamsport, Pa,, USA), andethoxylated oleyl alcohols (e.g., VOLPO-3, available from Croda, Inc.,N.Y., New York, USA). Other types of hydrophilizing agents andtechniques can also be used, including those well known to those skilledin the fiber and textile arts for increasing wicking performance,improving soil release properties, etc. Hydrophilizing agents can beadded to the polymer at various stages prior to use, though preferablyprior to drawing of the capillary channel fibers to their final size.For example, the hydrophilizing agent can be added in advance to thepolymer prior to melting or blended into the polymer subsequent tomelting. The additive hydrophilizing agent can also be applied to thepolymer subsequent to formation, e.g., subsequent to exit from anextrusion die in a melt, wet, or dry spinning process, preferably priorto drawing of the fiber to small diameter. Of course, since the articlesherein are intended to come into contact with sensitive regions of thehuman body, it is preferred that surfactants used to hydrophilize thesurfaces of the capillary channel fibers be nontoxic and nonirritatingto human skin. Various surfactant treatments for hydrophilizing thecapillary channel fibers are described in the Examples hereinafter.Another method for hydrophilizing fibrous surfaces involves subjectingsaid surfaces to ionizing radiation, e.g., in a plasma, and such methodshave the advantage that there is no surfactant residue on the surface ofthe fibers. Whatever the means, the overall objective is to securecapillary channel fibers for use herein which are spontaneously wettableby the fluids they are intended to transport.

(c). Various Forms of Capillary Channel Fibers

Preferably the capillary channel fibers 25 will be in the form of a yarnas illustrated in FIGS. 1 and 2. The yarn of capillary channel fibers 25is comprised of individual capillary channel fibers 25 which have beengathered after spinning. Small twists in the yarn of capillary channelfibers 25 provides cohesiveness among the fibers.

The capillary channel fibers 25 used in the yarn preferably have an"H"-shaped cross-section as illustrated in FIGS. 3. The "H"-shapedcapillary channel fibers 25 have a depth of walls of about 46 micronsand a width between walls of about 33 microns. The fibers have a denierof about 16. The denier of the yarn of capillary channel fibers is about657. The fibers are preferably helically curled and have an amplitude ofabout 0.15 mm and the frequency of the curls is about 8.3 per inch offiber.

In another embodiment the capillary channel fibers 25 may be in the formof a nonwoven. The nonwoven is preferably a thermally bonded, rebulkedand needled web comprised of 2 inch helically curled staple fibers.Other methods for forming the nonwoven include carding, rando process,spunbond, needlepunch, hydroentangled, and the like. The fibers have adenier per filament of about 17. The resultant nonwoven preferably has abasis weight of about 1.6 oz/yd². A suitable nonwoven comprised ofcapillary channel fibers is disclosed in U.S. Patent Applicationentitled "Fluid Accepting, Transporting, and Retaining Structure", Ser.No. filed Sep. 10, 1992, Inventors Thompson et al.

E. Fluid Flow Among the Various Layers

Initially fluid will impinge the topsheet 22 of the sanitary napkin 20.Fluid will then move through the topsheet 22 toward the flow regulator21, which preferably comprises the secondary topsheet 27 and the yarn ofcapillary channel fibers 25. The flow regulator 21 which separatestopsheet 22 from the absorbent core 24 prevents fluid from reaching theunderlying absorbent core 24 too rapidly. As fluid contacts the yarn ofcapillary channel fibers 25 located within the pleats 26 of thesecondary topsheet 27 fluid will be dispersed substantially in thelongitudinal direction of the sanitary napkin 20. In other words, theflow regulator comprising the secondary topsheet 21 and the capillarychannel fibers 25 facilitates longitudinal movement of the fluid ratherthan directly depositing the fluid onto the absorbent core 24 directlybelow the spot of impingement upon the topsheet 22.

The secondary topsheet 27 allows movement of fluid in the z-directiontoward the absorbent core 24 but at such a rate that a substantialportion of the fluid is first moved longitudinally by the capillarychannel fibers 25. Fluid is eventually allowed to penetrate thesecondary topsheet 27 and is surrendered to the absorbent core 24.

By moving bodily fluids in the longitudinal direction prior todepositing them upon or relinquishing them to the absorbent core 24,better utilization of the absorbent core 24 is achieved. By betterutilizing the entire absorbent core 24, side soiling can be reduced andfor all practical purposes eliminated.

This concept of longitudinal movement of bodily fluids prior torelinquishing the fluids to the absorbent core 24 is particularlyvaluable in situations where, as in sanitary napkins, the target zonefor bodily fluids is perhaps the narrowest portion of the sanitarynapkin 20. Therefore, the human anatomy forces the largest capacityzones for the absorbent core to be in the transverse direction.Therefore, a vast majority of the absorbent core 24 is not utilized.

The overall movement of bodily fluids can be viewed as a z-directionmovement and then a longitudinal movement followed by a z-directionmovement. That is, as bodily fluids are deposited upon the sanitarynapkin 20 they are first moved in the z-direction through the topsheet22. Bodily fluids are then moved in the longitudinal direction by theflow regulator 21 before being surrendered to the underlying absorbent24. As mentioned above, this allows the entire absorbent core 24 to beutilized more efficiently.

By moving fluids in the z-direction and then longitudinally followed bya z-direction movement, the capillary channel fibers 25 of the flowregulator 21 are "renewed" for the next infusion of fluid, therebyleaving the topsheet 22 with a fresh, dry appearance and feel. Thesanitary napkin 20 is able to continue the process until the absorbentcore 24 is saturated.

In order to move fluid among the various layers of the sanitary napkin20 it is important that the various layers are kept in close orotherwise intimate contact with one another. This contact can beachieved by a number of suitable methods. These include but are notlimited to bonding by adhesives, ultrasonics, and the like, or bytensional forces.

Thus, in a highly preferred mode there is an interconnecting networkbetween topsheet 22, thence into the capillary channel fibers 25 and thesecondary topsheet 27 of the flow regulator 21, and thence into theunderlying absorbent core 24, whereby fluid efficiently proceeds throughthe topsheet 22, along the capillary channel fibers 25, into thesecondary topsheet 27, and into the absorbent core 24. Thisinterconnection between the various layers is maintained even in theface of in-use stresses such as moisture, mechanical shear, andpressure-relaxation associated with physical movement of the wearer.

If the adhesive attachment is used, several factors should be kept inmind. The amounts of the adhesive used in a pattern in which it islaid-down should minimize the sticking of the absorbent article to theuser's body.

It will also be appreciated using excessive amounts of adhesives couldundesirably clog the capillary channels in the fibers 25, therebyreducing their effectiveness. Accordingly, "noninterfering" amounts ofadhesives are used. Such amounts can vary, depending on the adhesivechosen, the pattern in which it is laid down, the width of the capillarychannels and the fibers, and the like. Controlling the amount of theadhesive also serves to minimize the sticking of the articles to theuser's body.

The adhesive should be nonirritating to the skin and otherwisetoxicologically-acceptable for use in close contact with delicate bodytissues. The adhesive should maintain its bonding properties whenmoisture is not present, i.e., when the article is being manufactured,and most preferably, when moisture is present, i.e., when the article isbeing used.

The adhesive should bond both to the material used to manufacture thetopsheet and to the material used to manufacture the capillary channelfibers. If the topsheet or the fibers are surfaced-treated, e.g., in ahydrophilization process, the nature of the surface treated will have beconsidered when selecting the adhesive.

Typical adhesives useful herein include materials selected from latexadhesives and hot melt adhesives.

The adhesive can be laid down in a random pattern, however, it is mostpreferred that a spiral, or multiple spiral, pattern, be used. The linesof adhesives are applied to the underside or garment side of thetopsheet 22 in a spiral pattern using a 0.2 mm nozzle, but applicationsusing nozzles at least as large as 0.6 mm are satisfactory.Alternatively, a spot pattern can be used to apply the adhesive to thetopsheet 22, but is less preferred.

Suitable adhesives are available from Findley Adhesives, especially hotmelt adhesives 4031, and latex 8085. The type of adhesive can varysomewhat depending on the type of finish present on the capillarychannel fibers. Suitable finishes include Eastman's LK5483, LK5563 andmost preferably Eastman's LK5570, as well as the polymer available asMILEASE T, which is well-known in the detergency arts (see, for example,U.S. Pat. No. 4,132,680) as a fiber-coating ethyleneterephthalate/polyetholglycal terephthalate soil release polymer inwhich is available from ICI America.

The adhesives may be applied in an open pattern network of filaments ofadhesives as disclosed in U.S. Pat. No. 4,573,986 issued to Minetola etal. on Mar. 4, 1986. Some suitable attachment means that utilize an openpattern network filaments comprising several lines of adhesive filamentsis rolled into a spiral pattern art illustrated by the apparatus andmethods disclosed in U.S. Pat. No. 3,911,173 issued to Sprague, Jr. onOct. 7, 1975; U.S. Pat. No. 4,785,996 issued to Zieker et al. on Nov.22, 1978; and U.S. Pat. No. 4,842,666 issued Werenicz on Jun. 27, 1989.

Close contact between the topsheet and the underlying layer of capillarychannel fibers can be further improved by applying pressure during thegluing processing and/or by "combing" the uppermost capillary channelfibers to provide individual fibers protrusion which give better contactwith the adhesive.

F. Optional Retaining Means

In use, the sanitary napkin 20 can be held in place by any support meansor attachment means well-known for such purposes. Preferably, thesanitary napkin is placed in the user's undergarment or panty andsecured thereto by a fastener such as an adhesive 36. The adhesive 36provides a means for securing the sanitary napkin 20 in the crotchportion of the panty. Thus, a portion or all of the outer surface of thebacksheet 23 is coated with adhesive. Any adhesive or glue used in theart for such purposes can be used for the adhesive herein, withpressure-sensitive adhesives being preferred. Suitable adhesives areCentury A-305-IV manufactured by the Century Adhesives Corporation ofColumbus, Ohio; and Instant Lock 34-2823 manufactured by the nationalStarch and Chemical Company of Bridgewater, N.J. Suitable adhesivefasteners are also described in U.S. Pat. No. 4,917,697. Before thesanitary napkin is placed in use, the pressure-sensitive adhesive 36 istypically covered with a removable release liner 37 in order to keep theadhesive 36 from drying out or adhering to a surface other than thecrotch portion of the panty prior to use. Suitable release liners 37 arealso described in the above-referenced U.S. Pat. No. 4,917,697. Anycommercially available release liners commonly used for such purposescan be utilized herein. Non-limiting examples of suitable release linersare BL30MG-A Silox E1/0 and BL30MG-A Silox 4P/0 both of which aremanufactured by the Akrosil Corporation of Menasha, Wis. The sanitarynapkin 20 of the present invention is used by removing the release liner37 and thereafter placing the sanitary napkin 20 in a panty so that theadhesive 36 contacts the panty. The adhesive 36 maintains the sanitarynapkin in its position within the panty during use.

G. Optional Features

The sanitary napkin 20 may also be provided with two flaps 34, each ofwhich are adjacent to and extend laterally from the side edge of theabsorbent core. The flaps 34 are configured to drape over the edges ofthe wearer's panties in the crotch region so that the flaps 34 aredisposed between the edges of the wearer's panties and the thighs.

The flaps 34 serve as least two purposes. First, the flaps 34 help serveto prevent swelling of the wearer's body and panties by menstral fluid,preferably by forming a double wall barrier along the edges of thepanties. Second, the flaps 34 are preferably provided with attachmentmeans on their garments surface so that the flaps 34 can be folded backunder the panty and attached to garment facing side of the panty. Inthis way, the flaps 34 serve to keep the sanitary napkin 20 properlypositioned in the panty.

The flaps 34 can be constructed of various materials including materialssimilar to the topsheet, backsheet, tissue, or combinations of thesematerials. Further, the flaps 34 may be a separate element attached tothe main body portion of the napkin or can comprise extensions of thetopsheet 22 and the backsheet 23 (i.e., unitary).

A number of sanitary napkins having flaps suitable or adaptable for usewith the sanitary napkins of the present invention are disclosed in U.S.Pat. No. 4,687,478 entitled "Shaped Sanitary Napkin with Flaps", issuedto Van Tilburg on Aug. 18, 1987; U.S. Pat. No. 4,589,876 entitled"Sanitary Napkin", issued to Van Tilburg on May 20, 1986; and U.S. Pat.No. 4,608,047, entitled "Sanitary Napkin Attachment Means", issued toMedingly on Aug. 26, 1986.

H. Assembly of the Components of a Sanitary Napkin

A sanitary napkin is preferably assembled in the following manner. Forsimplicity, the assembly is described in terms of one possible method.The steps described below can be carried out in many other orders. Thereare also numerous other ways to assemble the sanitary napkins. All suchalternatives are within the scope of the present invention.

The secondary topsheet 27 is placed over a forming bar to form the firstpleat in the secondary topsheet 27. This process is repeated until 6-12pleats in all are formed in the secondary topsheet 27.

A yarn of capillary channel fibers 25 is then placed in each of thepleats 26 of the secondary topsheet 27. As can be seen some of the yarnof capillary channel fibers extends beyond the pleats of the secondarytopsheet 27. The yarns of capillary channel fibers 25 may be placed inthe pleats in a continuous strand, followed by snipping the yarnsegments that extend beyond the ends of the secondary topsheet 27. Oralternatively, individual yarns precut to length may be placed withineach pleat 26 of the secondary topsheet 27.

The underside of the topsheet 22 is then sprayed with an adhesive on itsgarment facing side. Preferably the adhesive is applied in spiralpattern to the garment side of the topsheet 22. The topsheet 22 is thenplaced on top of the pleated secondary topsheet 27 such that thecapillary channel fibers 25 are positioned between the topsheet 22 andthe secondary topsheet 27. Pressure is applied to achieve bonding.

Meanwhile the core 24 is secured to the body facing surface of thebacksheet 23 using an adhesive. Prior to securing the core 24 to thebacksheet 23 the components for the absorbent core 24 are obtained. Theabsorbent core 24 is preferably a laminate described above of two layersof cross-linked cellulosic fibers 41 and 42 with absorbent gellingparticles 40 there between. The absorbent gelling material particles 40are placed on top of the web (or bottom portion thereof) that will formthe bottom layer 42 of cross-linked cellulosic fibers. The upper layer41 of the core 24 is placed on top of the layered particles of absorbentgelling material 40. The components of the absorbent core are securedtogether by stitching or adhesive. The backsheet core assembly is thenplaced on the topsheet acquisition layer assembly which forms apreassembled sanitary napkin. The preassembled sanitary napkin is thenready to be sealed. The longitudinal side margins and end margins arethen sealed. In a preferred process the longitudinal side margins andthe end margins of the sanitary napkin are sealed by a heating element.The heating element is essentially used to "iron" the longitudinal sidemargins and the end margins together.

3. Alternative Embodiment of the Sanitary Napkin of the PresentInvention

FIG. 9 is a top plan view of another embodiment of the sanitary napkin60 of the present invention in its flat out state with portions of thestructure being cut-away to more clearly show the construction of thesanitary napkin 60 and with the portion of the sanitary napkin 60 whichfaces or contacts the wearer 60a, oriented towards the viewer. As shownin FIG. 9, the sanitary napkin 60 preferably comprises a liquid pervioustopsheet 62, a liquid impervious backsheet 63 joined with the topsheet62, an absorbent core 64 positioned between the topsheet 62 and thebacksheet 63, and flow regulator 61 positioned between the topsheet 62and the absorbent core 64. The flow regulator 61 is comprised of asecondary topsheet 66 and a nonwoven 65 comprised of fibers havingexternal capillary channels.

FIG. 10 is a cross-sectional view of the sanitary napkin 60 taken alongsection line 10--10 of FIG. 9. As can be seen in FIG. 10 the nonwoven 65comprised of fibers having external capillary channel fibers issuperposed on the body facing surface of the secondary topsheet 66.Together, the secondary topsheet and the nonwoven form the flowregulator 61. The flow regulator 61 is preferably arranged to form aplurality of pleats 67 extending substantially parallel to thelongitudinal direction of the sanitary napkin 60.

The sanitary napkin 60 has two surfaces, a body surface 60a and agarment surface 60b. A sanitary napkin 60 is shown in FIG. 9 as viewedfrom its body surface 60a. The body surface 60a is intended to be wornadjacent to the body of the wearer. The garment surface 60b of thesanitary napkin 60 (shown in FIG. 10) is on the opposite side and isintended to be placed adjacent to the wearer's undergarments when thesanitary napkin 60 is worn.

The sanitary napkin 60 preferably includes an adhesive fastening means71 for attaching the sanitary napkin 60 to the undergarment of thewearer. Removable release liners 72 cover the adhesive fastening means71 to keep the adhesive from sticking to a surface other than the crotchportion of the undergarment prior to use.

The backsheet 63, topsheet 62, core 64, adhesive 71 and release liner72, secondary topsheet 66 and nonwoven 65 are preferably comprised ofmaterials and constructions described more fully in detail above.

Preferably, the channels of the fibers of the nonwoven 65 are orientedsubstantially in the longitudinal direction. Thus, fluid deposited onthe nonwoven 65 is moved in the longitudinal direction prior to beingsurrendered to the secondary topsheet 66, which surrenders it theabsorbent core 64. This longitudinal fluid movement provides a moreeffective use of the absorbent core 64.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. An absorbent article having a longitudinaldirection, a transverse direction, and a z-direction, said absorbentarticle comprising:(a) a fluid pervious topsheet; (b) a fluid imperviousbacksheet joined to said topsheet; (c) an absorbent core positionedbetween said topsheet and said backsheet, said absorbent core having anuppermost surface facing said topsheet and a lowermost surface facingsaid backsheet; and (d) a flow regulator positioned between saidtopsheet and said absorbent core said flow regulator enhancing movementof fluid in the longitudinal direction while controlling movement offluid in the transverse and z-directions.
 2. The absorbent articleaccording to claim 1 wherein said flow regulator comprises a secondarytopsheet and a plurality of fibers having external capillary channels.3. The absorbent article according to claim 2 wherein said secondarytopsheet is arranged in a plurality of pleats extending substantiallyparallel to the longitudinal direction of said absorbent article.
 4. Theabsorbent article according to claim 3 wherein said fibers havingexternal capillary channels are formed into a yarn and positioned withinthe pleats of said secondary topsheet.
 5. The absorbent articleaccording to claim 3 wherein said fibers having external capillarychannels are formed into a nonwoven web, said nonwoven web is superposedupon said secondary topsheet.
 6. The absorbent article according toclaim 5 wherein said fibers having external capillary channels of saidnonwoven web are oriented such that their channels lie substantiallyparallel to the longitudinal direction of said article.
 7. The absorbentarticle according to claim 2 wherein said fibers having externalcapillary channels are hydrophilic.
 8. An absorbent article having alongitudinal direction, a transverse direction, and a z-direction, saidabsorbent article comprising:(a) a liquid pervious topsheet; (b) aliquid impervious backsheet joined to said topsheet; (c) an absorbentcore positioned between said topsheet and said backsheet, said absorbentcore having an uppermost surface facing said topsheet and a lowermostsurface facing said backsheet; (d) a secondary topsheet positionedbetween said topsheet and said absorbent core, said secondary topsheetbeing arranged in a plurality of pleats extending substantially parallelto the longitudinal direction of said absorbent article; and (e) aplurality of fibers having external capillary channels being positionedbetween said topsheet and said secondary topsheet within said pleats ofsaid secondary topsheet.
 9. The absorbent article according to claim 8wherein said fibers having external capillary channels are formed into ayarn.
 10. The absorbent article according to claim 9 wherein thecapillary channel fibers are hydrophilic.
 11. The absorbent articleaccording to claim 10 wherein the capillary channel fibers have a"H"-shaped cross-section.
 12. The absorbent article according to claim 9wherein the yarn of fibers having external capillary channels istwisted.
 13. The absorbent article according to claim 8 wherein saidabsorbent core comprises absorbent gelling material disposed between theuppermost and lowermost surfaces of said core.
 14. The absorbent articleaccording to claim 8 wherein said secondary topsheet is a tissue.
 15. Anabsorbent article having a longitudinal direction, a transversedirection, and a z-direction, said absorbent article comprising:(a) aliquid pervious topsheet; (b) a liquid impervious backsheet joined tosaid topsheet; (c) an absorbent core positioned between said topsheetand said backsheet, said absorbent core having an uppermost surfacefacing said topsheet and a lowermost surface facing said backsheet; (d)a secondary topsheet having a body facing surface and a garment facingsurface positioned between said topsheet and said backsheet, saidsecondary topsheet being arranged in a plurality of pleats extendingsubstantially parallel to the longitudinal direction of said absorbentarticle; and (e) a nonwoven web of fibers having external capillarychannels being positioned between said topsheet and said secondarytopsheet and being superposed on the body facing surface of saidsecondary topsheet.
 16. The absorbent article according to claim 15wherein said fibers having external capillary channels are oriented suchthat their channels lie substantially parallel to the longitudinaldirection of said article.
 17. The absorbent article according to claim16 wherein said fibers having external capillary channels arehydrophilic.
 18. The absorbent article according to claim 15 whereinsaid absorbent core comprises absorbent gelling material disposedbetween the uppermost and lowermost surfaces of said core.
 19. Theabsorbent article according to claim 15 wherein said secondary topsheetis at issue.